The present disclosure relates to an image processing method and an image processing apparatus, more particularly, to an image processing apparatus, an image pickup apparatus, and an image processing method that use a super-resolution technique of generating a super-resolution image by enhancing a resolution of an arbitrary input image.
From the past, as a super-resolution technique of enhancing a resolution of a low-resolution image and restoring information that cannot be restored by a normal enlargement method, there is a method of performing super-resolution processing using a high-frequency component included in an image (see Japanese Patent Application Laid-open No. 2011-171843; hereinafter referred to as Patent Document 1). In the method disclosed in Patent Document 1, it is necessary to create a low-resolution image from a high-resolution image and learn data in advance as a preparation stage for carrying out the super-resolution processing and obtain an interpolation filter coefficient defining a conversion relationship (learning step). Then, using the interpolation filter coefficient obtained in the learning step, a high-resolution output image is obtained from an arbitrary low-resolution input image (restoration step).
Further, as another method of performing super-resolution processing using a high-frequency component included in an image, there is a technique of using matching processing (block matching) for estimating a pixel position to which the high-frequency component is to be applied in an enlarged image (see Japanese Patent Application Laid-open No. 2011-524714; hereinafter, referred to as Patent Document 2).